/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.tribes;

/**
 * The Member interface, defines a member in the group.
 * Each member can carry a set of properties, defined by the actual implementation.<BR>
 * A member is identified by the host/ip/uniqueId<br>
 * The host is what interface the member is listening to, to receive data<br>
 * The port is what port the member is listening to, to receive data<br>
 * The uniqueId defines the session id for the member. This is an important feature
 * since a member that has crashed and the starts up again on the same port/host is
 * not guaranteed to be the same member, so no state transfers will ever be confused
 *
 * @author Filip Hanik
 */
public interface Member {

	/**
	 * When a member leaves the cluster, the payload of the memberDisappeared member
	 * will be the following bytes. This indicates a soft shutdown, and not a crash
	 */
	public static final byte[] SHUTDOWN_PAYLOAD = new byte[]{66, 65, 66, 89, 45, 65, 76, 69, 88};

	/**
	 * Returns the name of this node, should be unique within the group.
	 */
	public String getName();

	/**
	 * Returns the listen host for the ChannelReceiver implementation
	 *
	 * @return IPv4 or IPv6 representation of the host address this member listens to incoming data
	 * @see ChannelReceiver
	 */
	public byte[] getHost();

	/**
	 * Returns the listen port for the ChannelReceiver implementation
	 *
	 * @return the listen port for this member, -1 if its not listening on an insecure port
	 * @see ChannelReceiver
	 */
	public int getPort();

	/**
	 * Returns the secure listen port for the ChannelReceiver implementation.
	 * Returns -1 if its not listening to a secure port.
	 *
	 * @return the listen port for this member, -1 if its not listening on a secure port
	 * @see ChannelReceiver
	 */
	public int getSecurePort();

	/**
	 * Returns the UDP port that this member is listening to for UDP messages.
	 *
	 * @return the listen UDP port for this member, -1 if its not listening on a UDP port
	 */
	public int getUdpPort();

	/**
	 * Contains information on how long this member has been online.
	 * The result is the number of milli seconds this member has been
	 * broadcasting its membership to the group.
	 *
	 * @return nr of milliseconds since this member started.
	 */
	public long getMemberAliveTime();

	/**
	 * The current state of the member
	 *
	 * @return boolean - true if the member is functioning correctly
	 */
	public boolean isReady();

	/**
	 * The current state of the member
	 *
	 * @return boolean - true if the member is suspect, but the crash has not been confirmed
	 */
	public boolean isSuspect();

	/**
	 * @return boolean - true if the member has been confirmed to malfunction
	 */
	public boolean isFailing();

	/**
	 * returns a UUID unique for this member over all sessions.
	 * If the member crashes and restarts, the uniqueId will be different.
	 *
	 * @return byte[]
	 */
	public byte[] getUniqueId();

	/**
	 * returns the payload associated with this member
	 *
	 * @return byte[]
	 */
	public byte[] getPayload();

	/**
	 * returns the command associated with this member
	 *
	 * @return byte[]
	 */
	public byte[] getCommand();

	/**
	 * Domain for this cluster
	 *
	 * @return byte[]
	 */
	public byte[] getDomain();
}
